60 birds were recorded seen in Oregon in September in our iNaturalist sample; 5 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.
Top birds in September

Mallard

Great Blue Heron

Turkey Vulture
California Scrub-Jay

Steller's Jay

Red-tailed Hawk

American Crow

Northern Flicker

Song Sparrow

Dark-eyed Junco
Anna's Hummingbird

Great Egret
All birds seen in Oregon in September
| # | Species | Scientific name | Family | Obs. | Peak in state |
|---|---|---|---|---|---|
| 1 | Mallard | Anas platyrhynchos | Ducks, Geese, and Swans | 936 | Apr (past peak) |
| 2 | Great Blue Heron | Ardea herodias | Herons, Egrets, and Bitterns | 843 | May (past peak) |
| 3 | Turkey Vulture | Cathartes aura | New World Vultures | 734 | May (past peak) |
| 4 | California Scrub-Jay | Aphelocoma californica | Crows, Jays, and Magpies | 716 | May (past peak) |
| 5 | Steller's Jay | Cyanocitta stelleri | Crows, Jays, and Magpies | 623 | May (past peak) |
| 6 | Red-tailed Hawk | Buteo jamaicensis | Hawks, Eagles, and Kites | 575 | Jan (past peak) |
| 7 | American Crow | Corvus brachyrhynchos | Crows, Jays, and Magpies | 551 | Mar (past peak) |
| 8 | Northern Flicker | Colaptes auratus | Woodpeckers | 541 | Mar (past peak) |
| 9 | Song Sparrow | Melospiza melodia | New World Sparrows | 488 | Mar (past peak) |
| 10 | Dark-eyed Junco | Junco hyemalis | New World Sparrows | 483 | Jan (past peak) |
| 11 | Anna's Hummingbird | Calypte anna | Hummingbirds | 480 | Mar (past peak) |
| 12 | Great Egret | Ardea alba | Herons, Egrets, and Bitterns | 454 | Sep (peak) |
| 13 | Cedar Waxwing | Bombycilla cedrorum | Waxwings | 430 | Jun (past peak) |
| 14 | Red-breasted Nuthatch | Sitta canadensis | Nuthatches | 416 | Sep (peak) |
| 15 | White-crowned Sparrow | Zonotrichia leucophrys | New World Sparrows | 409 | Apr (past peak) |
| 16 | Canada Goose | Branta canadensis | Ducks, Geese, and Swans | 386 | Apr (past peak) |
| 17 | Black-capped Chickadee | Poecile atricapillus | Tits, Chickadees, and Titmice | 377 | Mar (past peak) |
| 18 | Western Gull | Larus occidentalis | Gulls, Terns, and Skimmers | 357 | Jul (past peak) |
| 19 | American Robin | Turdus migratorius | Thrushes | 348 | May (past peak) |
| 20 | House Finch | Haemorhous mexicanus | Finches, Euphonias, and Allies | 327 | May (past peak) |
| 21 | Downy Woodpecker | Dryobates pubescens | Woodpeckers | 327 | Jan (past peak) |
| 22 | Wild Turkey | Meleagris gallopavo | Pheasants, Grouse, and Allies | 326 | Apr (past peak) |
| 23 | American White Pelican | Pelecanus erythrorhynchos | Pelicans | 325 | Sep (peak) |
| 24 | American Goldfinch | Spinus tristis | Finches, Euphonias, and Allies | 323 | May (past peak) |
| 25 | Spotted Towhee | Pipilo maculatus | New World Sparrows | 310 | Apr (past peak) |
| 26 | Greater Yellowlegs | Tringa melanoleuca | Sandpipers and Allies | 292 | Apr (past peak) |
| 27 | Lesser Goldfinch | Spinus psaltria | Finches, Euphonias, and Allies | 285 | May (past peak) |
| 28 | Wood Duck | Aix sponsa | Ducks, Geese, and Swans | 284 | May (past peak) |
| 29 | Brewer's Blackbird | Euphagus cyanocephalus | New World Blackbirds and Orioles | 283 | May (past peak) |
| 30 | Pied-billed Grebe | Podilymbus podiceps | Grebes | 279 | Sep (peak) |
| 31 | Cooper's Hawk | Astur cooperii | Hawks, Eagles, and Kites | 279 | Aug (past peak) |
| 32 | Osprey | Pandion haliaetus | Ospreys | 267 | Jul (past peak) |
| 33 | Mourning Dove | Zenaida macroura | Pigeons and Doves | 252 | May (past peak) |
| 34 | Golden-crowned Sparrow | Zonotrichia atricapilla | New World Sparrows | 250 | Apr (past peak) |
| 35 | American Kestrel | Falco sparverius | Falcons and Caracaras | 249 | Jan (past peak) |
| 36 | Canada Jay | Perisoreus canadensis | Crows, Jays, and Magpies | 246 | Sep (peak) |
| 37 | Savannah Sparrow | Passerculus sandwichensis | New World Sparrows | 246 | Apr (past peak) |
| 38 | Brown Pelican | Pelecanus occidentalis | Pelicans | 241 | Aug (past peak) |
| 39 | European Starling | Sturnus vulgaris | Starlings | 237 | May (past peak) |
| 40 | Green Heron | Butorides virescens | Herons, Egrets, and Bitterns | 233 | Aug (past peak) |
| 41 | Killdeer | Charadrius vociferus | Plovers and Lapwings | 222 | May (past peak) |
| 42 | Belted Kingfisher | Megaceryle alcyon | Kingfishers | 216 | Aug (past peak) |
| 43 | Barred Owl | Strix varia | Typical Owls | 213 | Jul (past peak) |
| 44 | Double-crested Cormorant | Nannopterum auritum | Cormorants and Shags | 212 | Jan (past peak) |
| 45 | Bushtit | Psaltriparus minimus | Long-tailed Tits and Bushtits | 207 | Mar (past peak) |
| 46 | California Gull | Larus californicus | Gulls, Terns, and Skimmers | 205 | Oct (rising) |
| 47 | Western Sandpiper | Calidris mauri | Sandpipers and Allies | 201 | Aug (past peak) |
| 48 | Common Raven | Corvus corax | Crows, Jays, and Magpies | 200 | May (past peak) |
| 49 | Ring-billed Gull | Larus delawarensis | Gulls, Terns, and Skimmers | 193 | Oct (rising) |
| 50 | Chestnut-backed Chickadee | Poecile rufescens | Tits, Chickadees, and Titmice | 191 | Aug (past peak) |